This invention relates to a method of and apparatus for making mouldings each comprising at least two moulded components, which in a first working step are each separately moulded and pre-hardened, for example by injection-moulding and pre-vulcanisation of rubber materials, and in a second working step are put together and hardened, especially finally vulcanised, with one another.
In various technical fields, mouldings of elastic, mouldable material, for example rubber or synthetic plastics material, are required which by reason of their configuration or properties of the material must be assembled from two or more moulded components. This requirement arises in the case of shoe soles comprising an inner or intermediate sole of cheaper or softer material facing the shoe upper and an outer sole of harder or abrasion-resistant material. Another example is "Tyton" sealing rings for pipe couplings and the like, which must have a higher elasticity in one partial zone and a higher degree of shape stability in another cross-sectional zone.
In the processing of rubber materials it is desirable to produce mouldings of this kind from moulded components in a manner in which firstly the moulded components are manufactured with partial consolidation, especially pre-vulcanisation, and then in a further working step connected with one another and hardened or finally vulcanised.
For the production of hollow bodies closed upon themselves, such as tires, inner tubes, etc., of elastomer materials, an apparatus is known in which by appropriately formed component moulds and a separator plate arranged between them, in a first working step two half mouldings are formed and pre-vulcanised. Then the separator plate between the component moulds is extracted and these are brought together until they abut. The half mouldings, now likewise abutting on one another, are pressed together, thereby becoming connected with one another and vulcanised out to form a closed moulding. During the first working step the material is fed to the two component mould pockets through an injection passage system simultaneously by one common injection unit. Accordingly, this known apparatus is not suitable for the production of mouldings of materials of different natures. Furthermore its output capacity is unsatisfactory (German DTOS No. 2,156,396).